drivers/leds/leds-netxbig.c

   1 /*
   2  * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
   3  *
   4  * Copyright (C) 2010 LaCie
   5  *
   6  * Author: Simon Guinot <sguinot@lacie.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/irq.h>
  25 #include <linux/slab.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/gpio.h>
  29 #include <linux/of_gpio.h>
  30 #include <linux/leds.h>
  31 #include <linux/platform_data/leds-kirkwood-netxbig.h>
  32
  33 /*
  34  * GPIO extension bus.
  35  */
  36
  37 static DEFINE_SPINLOCK(gpio_ext_lock);
  38
  39 static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  40 {
  41         int pin;
  42
  43         for (pin = 0; pin < gpio_ext->num_addr; pin++)
  44                 gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  45 }
  46
  47 static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  48 {
  49         int pin;
  50
  51         for (pin = 0; pin < gpio_ext->num_data; pin++)
  52                 gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  53 }
  54
  55 static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  56 {
  57         /* Enable select is done on the raising edge. */
  58         gpio_set_value(gpio_ext->enable, 0);
  59         gpio_set_value(gpio_ext->enable, 1);
  60 }
  61
  62 static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  63                                int addr, int value)
  64 {
  65         unsigned long flags;
  66
  67         spin_lock_irqsave(&gpio_ext_lock, flags);
  68         gpio_ext_set_addr(gpio_ext, addr);
  69         gpio_ext_set_data(gpio_ext, value);
  70         gpio_ext_enable_select(gpio_ext);
  71         spin_unlock_irqrestore(&gpio_ext_lock, flags);
  72 }
  73
  74 static int gpio_ext_init(struct platform_device *pdev,
  75                          struct netxbig_gpio_ext *gpio_ext)
  76 {
  77         int err;
  78         int i;
  79
  80         if (unlikely(!gpio_ext))
  81                 return -EINVAL;
  82
  83         /* Configure address GPIOs. */
  84         for (i = 0; i < gpio_ext->num_addr; i++) {
  85                 err = devm_gpio_request_one(&pdev->dev, gpio_ext->addr[i],
  86                                             GPIOF_OUT_INIT_LOW,
  87                                             "GPIO extension addr");
  88                 if (err)
  89                         return err;
  90         }
  91         /* Configure data GPIOs. */
  92         for (i = 0; i < gpio_ext->num_data; i++) {
  93                 err = devm_gpio_request_one(&pdev->dev, gpio_ext->data[i],
  94                                             GPIOF_OUT_INIT_LOW,
  95                                             "GPIO extension data");
  96                 if (err)
  97                         return err;
  98         }
  99         /* Configure "enable select" GPIO. */
 100         err = devm_gpio_request_one(&pdev->dev, gpio_ext->enable,
 101                                     GPIOF_OUT_INIT_LOW,
 102                                     "GPIO extension enable");
 103         if (err)
 104                 return err;
 105
 106         return 0;
 107 }
 108
 109 /*
 110  * Class LED driver.
 111  */
 112
 113 struct netxbig_led_data {
 114         struct netxbig_gpio_ext *gpio_ext;
 115         struct led_classdev     cdev;
 116         int                     mode_addr;
 117         int                     *mode_val;
 118         int                     bright_addr;
 119         struct                  netxbig_led_timer *timer;
 120         int                     num_timer;
 121         enum netxbig_led_mode   mode;
 122         int                     sata;
 123         spinlock_t              lock;
 124 };
 125
 126 static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 127                                       unsigned long delay_on,
 128                                       unsigned long delay_off,
 129                                       struct netxbig_led_timer *timer,
 130                                       int num_timer)
 131 {
 132         int i;
 133
 134         for (i = 0; i < num_timer; i++) {
 135                 if (timer[i].delay_on == delay_on &&
 136                     timer[i].delay_off == delay_off) {
 137                         *mode = timer[i].mode;
 138                         return 0;
 139                 }
 140         }
 141         return -EINVAL;
 142 }
 143
 144 static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 145                                  unsigned long *delay_on,
 146                                  unsigned long *delay_off)
 147 {
 148         struct netxbig_led_data *led_dat =
 149                 container_of(led_cdev, struct netxbig_led_data, cdev);
 150         enum netxbig_led_mode mode;
 151         int mode_val;
 152         int ret;
 153
 154         /* Look for a LED mode with the requested timer frequency. */
 155         ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 156                                          led_dat->timer, led_dat->num_timer);
 157         if (ret < 0)
 158                 return ret;
 159
 160         mode_val = led_dat->mode_val[mode];
 161         if (mode_val == NETXBIG_LED_INVALID_MODE)
 162                 return -EINVAL;
 163
 164         spin_lock_irq(&led_dat->lock);
 165
 166         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 167         led_dat->mode = mode;
 168
 169         spin_unlock_irq(&led_dat->lock);
 170
 171         return 0;
 172 }
 173
 174 static void netxbig_led_set(struct led_classdev *led_cdev,
 175                             enum led_brightness value)
 176 {
 177         struct netxbig_led_data *led_dat =
 178                 container_of(led_cdev, struct netxbig_led_data, cdev);
 179         enum netxbig_led_mode mode;
 180         int mode_val;
 181         int set_brightness = 1;
 182         unsigned long flags;
 183
 184         spin_lock_irqsave(&led_dat->lock, flags);
 185
 186         if (value == LED_OFF) {
 187                 mode = NETXBIG_LED_OFF;
 188                 set_brightness = 0;
 189         } else {
 190                 if (led_dat->sata)
 191                         mode = NETXBIG_LED_SATA;
 192                 else if (led_dat->mode == NETXBIG_LED_OFF)
 193                         mode = NETXBIG_LED_ON;
 194                 else /* Keep 'timer' mode. */
 195                         mode = led_dat->mode;
 196         }
 197         mode_val = led_dat->mode_val[mode];
 198
 199         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 200         led_dat->mode = mode;
 201         /*
 202          * Note that the brightness register is shared between all the
 203          * SATA LEDs. So, change the brightness setting for a single
 204          * SATA LED will affect all the others.
 205          */
 206         if (set_brightness)
 207                 gpio_ext_set_value(led_dat->gpio_ext,
 208                                    led_dat->bright_addr, value);
 209
 210         spin_unlock_irqrestore(&led_dat->lock, flags);
 211 }
 212
 213 static ssize_t netxbig_led_sata_store(struct device *dev,
 214                                       struct device_attribute *attr,
 215                                       const char *buff, size_t count)
 216 {
 217         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 218         struct netxbig_led_data *led_dat =
 219                 container_of(led_cdev, struct netxbig_led_data, cdev);
 220         unsigned long enable;
 221         enum netxbig_led_mode mode;
 222         int mode_val;
 223         int ret;
 224
 225         ret = kstrtoul(buff, 10, &enable);
 226         if (ret < 0)
 227                 return ret;
 228
 229         enable = !!enable;
 230
 231         spin_lock_irq(&led_dat->lock);
 232
 233         if (led_dat->sata == enable) {
 234                 ret = count;
 235                 goto exit_unlock;
 236         }
 237
 238         if (led_dat->mode != NETXBIG_LED_ON &&
 239             led_dat->mode != NETXBIG_LED_SATA)
 240                 mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 241         else if (enable)
 242                 mode = NETXBIG_LED_SATA;
 243         else
 244                 mode = NETXBIG_LED_ON;
 245
 246         mode_val = led_dat->mode_val[mode];
 247         if (mode_val == NETXBIG_LED_INVALID_MODE) {
 248                 ret = -EINVAL;
 249                 goto exit_unlock;
 250         }
 251
 252         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 253         led_dat->mode = mode;
 254         led_dat->sata = enable;
 255
 256         ret = count;
 257
 258 exit_unlock:
 259         spin_unlock_irq(&led_dat->lock);
 260
 261         return ret;
 262 }
 263
 264 static ssize_t netxbig_led_sata_show(struct device *dev,
 265                                      struct device_attribute *attr, char *buf)
 266 {
 267         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 268         struct netxbig_led_data *led_dat =
 269                 container_of(led_cdev, struct netxbig_led_data, cdev);
 270
 271         return sprintf(buf, "%d\n", led_dat->sata);
 272 }
 273
 274 static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 275
 276 static struct attribute *netxbig_led_attrs[] = {
 277         &dev_attr_sata.attr,
 278         NULL
 279 };
 280 ATTRIBUTE_GROUPS(netxbig_led);
 281
 282 static int create_netxbig_led(struct platform_device *pdev,
 283                               struct netxbig_led_platform_data *pdata,
 284                               struct netxbig_led_data *led_dat,
 285                               const struct netxbig_led *template)
 286 {
 287         spin_lock_init(&led_dat->lock);
 288         led_dat->gpio_ext = pdata->gpio_ext;
 289         led_dat->cdev.name = template->name;
 290         led_dat->cdev.default_trigger = template->default_trigger;
 291         led_dat->cdev.blink_set = netxbig_led_blink_set;
 292         led_dat->cdev.brightness_set = netxbig_led_set;
 293         /*
 294          * Because the GPIO extension bus don't allow to read registers
 295          * value, there is no way to probe the LED initial state.
 296          * So, the initial sysfs LED value for the "brightness" and "sata"
 297          * attributes are inconsistent.
 298          *
 299          * Note that the initial LED state can't be reconfigured.
 300          * The reason is that the LED behaviour must stay uniform during
 301          * the whole boot process (bootloader+linux).
 302          */
 303         led_dat->sata = 0;
 304         led_dat->cdev.brightness = LED_OFF;
 305         led_dat->cdev.max_brightness = template->bright_max;
 306         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 307         led_dat->mode_addr = template->mode_addr;
 308         led_dat->mode_val = template->mode_val;
 309         led_dat->bright_addr = template->bright_addr;
 310         led_dat->timer = pdata->timer;
 311         led_dat->num_timer = pdata->num_timer;
 312         /*
 313          * If available, expose the SATA activity blink capability through
 314          * a "sata" sysfs attribute.
 315          */
 316         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 317                 led_dat->cdev.groups = netxbig_led_groups;
 318
 319         return devm_led_classdev_register(&pdev->dev, &led_dat->cdev);
 320 }
 321
 322 #ifdef CONFIG_OF_GPIO
 323 static int gpio_ext_get_of_pdata(struct device *dev, struct device_node *np,
 324                                  struct netxbig_gpio_ext *gpio_ext)
 325 {
 326         int *addr, *data;
 327         int num_addr, num_data;
 328         int ret;
 329         int i;
 330
 331         ret = of_gpio_named_count(np, "addr-gpios");
 332         if (ret < 0) {
 333                 dev_err(dev,
 334                         "Failed to count GPIOs in DT property addr-gpios\n");
 335                 return ret;
 336         }
 337         num_addr = ret;
 338         addr = devm_kzalloc(dev, num_addr * sizeof(*addr), GFP_KERNEL);
 339         if (!addr)
 340                 return -ENOMEM;
 341
 342         for (i = 0; i < num_addr; i++) {
 343                 ret = of_get_named_gpio(np, "addr-gpios", i);
 344                 if (ret < 0)
 345                         return ret;
 346                 addr[i] = ret;
 347         }
 348         gpio_ext->addr = addr;
 349         gpio_ext->num_addr = num_addr;
 350
 351         ret = of_gpio_named_count(np, "data-gpios");
 352         if (ret < 0) {
 353                 dev_err(dev,
 354                         "Failed to count GPIOs in DT property data-gpios\n");
 355                 return ret;
 356         }
 357         num_data = ret;
 358         data = devm_kzalloc(dev, num_data * sizeof(*data), GFP_KERNEL);
 359         if (!data)
 360                 return -ENOMEM;
 361
 362         for (i = 0; i < num_data; i++) {
 363                 ret = of_get_named_gpio(np, "data-gpios", i);
 364                 if (ret < 0)
 365                         return ret;
 366                 data[i] = ret;
 367         }
 368         gpio_ext->data = data;
 369         gpio_ext->num_data = num_data;
 370
 371         ret = of_get_named_gpio(np, "enable-gpio", 0);
 372         if (ret < 0) {
 373                 dev_err(dev,
 374                         "Failed to get GPIO from DT property enable-gpio\n");
 375                 return ret;
 376         }
 377         gpio_ext->enable = ret;
 378
 379         return 0;
 380 }
 381
 382 static int netxbig_leds_get_of_pdata(struct device *dev,
 383                                      struct netxbig_led_platform_data *pdata)
 384 {
 385         struct device_node *np = dev->of_node;
 386         struct device_node *gpio_ext_np;
 387         struct device_node *child;
 388         struct netxbig_gpio_ext *gpio_ext;
 389         struct netxbig_led_timer *timers;
 390         struct netxbig_led *leds, *led;
 391         int num_timers;
 392         int num_leds = 0;
 393         int ret;
 394         int i;
 395
 396         /* GPIO extension */
 397         gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
 398         if (!gpio_ext_np) {
 399                 dev_err(dev, "Failed to get DT handle gpio-ext\n");
 400                 return -EINVAL;
 401         }
 402
 403         gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
 404         if (!gpio_ext)
 405                 return -ENOMEM;
 406         ret = gpio_ext_get_of_pdata(dev, gpio_ext_np, gpio_ext);
 407         if (ret)
 408                 return ret;
 409         of_node_put(gpio_ext_np);
 410         pdata->gpio_ext = gpio_ext;
 411
 412         /* Timers (optional) */
 413         ret = of_property_count_u32_elems(np, "timers");
 414         if (ret > 0) {
 415                 if (ret % 3)
 416                         return -EINVAL;
 417                 num_timers = ret / 3;
 418                 timers = devm_kzalloc(dev, num_timers * sizeof(*timers),
 419                                       GFP_KERNEL);
 420                 if (!timers)
 421                         return -ENOMEM;
 422                 for (i = 0; i < num_timers; i++) {
 423                         u32 tmp;
 424
 425                         of_property_read_u32_index(np, "timers", 3 * i,
 426                                                    &timers[i].mode);
 427                         if (timers[i].mode >= NETXBIG_LED_MODE_NUM)
 428                                 return -EINVAL;
 429                         of_property_read_u32_index(np, "timers",
 430                                                    3 * i + 1, &tmp);
 431                         timers[i].delay_on = tmp;
 432                         of_property_read_u32_index(np, "timers",
 433                                                    3 * i + 2, &tmp);
 434                         timers[i].delay_off = tmp;
 435                 }
 436                 pdata->timer = timers;
 437                 pdata->num_timer = num_timers;
 438         }
 439
 440         /* LEDs */
 441         num_leds = of_get_child_count(np);
 442         if (!num_leds) {
 443                 dev_err(dev, "No LED subnodes found in DT\n");
 444                 return -ENODEV;
 445         }
 446
 447         leds = devm_kzalloc(dev, num_leds * sizeof(*leds), GFP_KERNEL);
 448         if (!leds)
 449                 return -ENOMEM;
 450
 451         led = leds;
 452         for_each_child_of_node(np, child) {
 453                 const char *string;
 454                 int *mode_val;
 455                 int num_modes;
 456
 457                 ret = of_property_read_u32(child, "mode-addr",
 458                                            &led->mode_addr);
 459                 if (ret)
 460                         goto err_node_put;
 461
 462                 ret = of_property_read_u32(child, "bright-addr",
 463                                            &led->bright_addr);
 464                 if (ret)
 465                         goto err_node_put;
 466
 467                 ret = of_property_read_u32(child, "max-brightness",
 468                                            &led->bright_max);
 469                 if (ret)
 470                         goto err_node_put;
 471
 472                 mode_val =
 473                         devm_kzalloc(dev,
 474                                      NETXBIG_LED_MODE_NUM * sizeof(*mode_val),
 475                                      GFP_KERNEL);
 476                 if (!mode_val) {
 477                         ret = -ENOMEM;
 478                         goto err_node_put;
 479                 }
 480
 481                 for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
 482                         mode_val[i] = NETXBIG_LED_INVALID_MODE;
 483
 484                 ret = of_property_count_u32_elems(child, "mode-val");
 485                 if (ret < 0 || ret % 2) {
 486                         ret = -EINVAL;
 487                         goto err_node_put;
 488                 }
 489                 num_modes = ret / 2;
 490                 if (num_modes > NETXBIG_LED_MODE_NUM) {
 491                         ret = -EINVAL;
 492                         goto err_node_put;
 493                 }
 494
 495                 for (i = 0; i < num_modes; i++) {
 496                         int mode;
 497                         int val;
 498
 499                         of_property_read_u32_index(child,
 500                                                    "mode-val", 2 * i, &mode);
 501                         of_property_read_u32_index(child,
 502                                                    "mode-val", 2 * i + 1, &val);
 503                         if (mode >= NETXBIG_LED_MODE_NUM) {
 504                                 ret = -EINVAL;
 505                                 goto err_node_put;
 506                         }
 507                         mode_val[mode] = val;
 508                 }
 509                 led->mode_val = mode_val;
 510
 511                 if (!of_property_read_string(child, "label", &string))
 512                         led->name = string;
 513                 else
 514                         led->name = child->name;
 515
 516                 if (!of_property_read_string(child,
 517                                              "linux,default-trigger", &string))
 518                         led->default_trigger = string;
 519
 520                 led++;
 521         }
 522
 523         pdata->leds = leds;
 524         pdata->num_leds = num_leds;
 525
 526         return 0;
 527
 528 err_node_put:
 529         of_node_put(child);
 530         return ret;
 531 }
 532
 533 static const struct of_device_id of_netxbig_leds_match[] = {
 534         { .compatible = "lacie,netxbig-leds", },
 535         {},
 536 };
 537 #else
 538 static inline int
 539 netxbig_leds_get_of_pdata(struct device *dev,
 540                           struct netxbig_led_platform_data *pdata)
 541 {
 542         return -ENODEV;
 543 }
 544 #endif /* CONFIG_OF_GPIO */
 545
 546 static int netxbig_led_probe(struct platform_device *pdev)
 547 {
 548         struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 549         struct netxbig_led_data *leds_data;
 550         int i;
 551         int ret;
 552
 553         if (!pdata) {
 554                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 555                 if (!pdata)
 556                         return -ENOMEM;
 557                 ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
 558                 if (ret)
 559                         return ret;
 560         }
 561
 562         leds_data = devm_kzalloc(&pdev->dev,
 563                                  pdata->num_leds * sizeof(*leds_data),
 564                                  GFP_KERNEL);
 565         if (!leds_data)
 566                 return -ENOMEM;
 567
 568         ret = gpio_ext_init(pdev, pdata->gpio_ext);
 569         if (ret < 0)
 570                 return ret;
 571
 572         for (i = 0; i < pdata->num_leds; i++) {
 573                 ret = create_netxbig_led(pdev, pdata,
 574                                          &leds_data[i], &pdata->leds[i]);
 575                 if (ret < 0)
 576                         return ret;
 577         }
 578
 579         return 0;
 580 }
 581
 582 static struct platform_driver netxbig_led_driver = {
 583         .probe          = netxbig_led_probe,
 584         .driver         = {
 585                 .name           = "leds-netxbig",
 586                 .of_match_table = of_match_ptr(of_netxbig_leds_match),
 587         },
 588 };
 589
 590 module_platform_driver(netxbig_led_driver);
 591
 592 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 593 MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 594 MODULE_LICENSE("GPL");
 595 MODULE_ALIAS("platform:leds-netxbig");